1. Field of the Invention
The present invention relates generally to an imaging apparatus and particularly to an imaging apparatus having a scan head that is raisable to a position for scanning a media sheet in the media conveying path of an automatic document feeder (ADF).
2. Description of the Related Art
An imaging apparatus, such as a copier, scanner, or a multi-function printing device (MFP) may include a scanning mechanism that operates in an ADF mode and/or a manual mode. A media sheet, such as paper or a transparency, when placed in an ADF or on a flatbed, is scanned by the imaging apparatus.
FIG. 1 shows an existing imaging apparatus 10 that includes an ADF 12, an imaging surface 14 and an imaging surface 16. The imaging apparatus 10 works in two modes, ADF mode and manual mode. In manual mode, each media sheet is manually placed on the imaging surface 16 where the scanning operation takes place. Below the imaging surface 16, a scan head (not shown) moves laterally in order to scan the media sheet. After the media sheet is scanned by the imaging apparatus 10, the media sheet must be manually removed from the imaging surface 16 prior to placing a second media sheet on the imaging surface 16 for scanning.
In ADF mode, manual feeding and removal of the media sheet is not required. The media sheet or a stack of media sheets are placed in a media feeding section 18. Each media sheet is then automatically sequentially fed by the ADF 12 through a portion of the imaging apparatus 10 for scanning. When scanning the media sheet is complete, the scanned media sheet is automatically driven out of the imaging apparatus 10 to a media collecting section 20. While scanning in ADF mode, the scan head generally does not move. Rather, the scan head is positioned beneath the imaging surface 14 for scanning the media thereon. The media sheet travels from the media feeding section 18 over the imaging surface 14 to the media collecting section 20. An ADF ramp 22 is disposed adjacent to the imaging surface 14. The ADF ramp 22 guides the media sheet towards the media collecting section 20 as the media sheet passes through the ADF.
FIGS. 2 and 3 show the media path of the ADF of the above-described imaging apparatus 10. A plurality of conveyors 24 are shown for transferring the media sheet from the media feeding section 18 to the media collecting section 20. While travelling from the media feeding section 18 to the media collecting section 20, the media sheet passes over the imaging surface 14, at which point a scan head 26 positioned beneath the imaging surface 14 scans the sheet. ADF ramp 22 guides the media sheet towards the media collecting section 20.
As shown in FIG. 3, portions of the media conveying path adjacent to the imaging surface 14 are substantially circular, which has been seen to adversely affect the smooth transfer of media sheet to the media collecting section 20 and lead to paper jams and motion shocks in the media conveying path.